Device for electrical purification of gases



Oct. 9, 1934. BRlQN ET AL 1 1,976,214

DEVICE FOR ELECTRICAL PURIFICATION OF GASES Filed Sept. 9, 1929 v 6 i 8% i L I Georg Brion- Johonrres Kvu+zsh FNVENTORs 111.45. Amrmy.

Patented Oct. 9, 1934 UNITED STATES DEVICE FOR ELECTRICAL PURIFICATION F GASES Georg Brion and Johannes Krutzsch, Freiberg,

' Germany Applicatlign September 9, 1929, Serial No. 391,503

Germany September 17, 1928 lit and electrons to the electrodes, thereby setting up a current. This double duty of the voltage Y often leads to diificulties and waste of power. For example, where two electrodes are placed at a considerable distance from each other, a very 115 high voltage is necessary for the ionization, whereas the ions and electrons formed could be moved toward the electrodes by a much lower voltage.

In order to overcome this difliculty it has been suggested to subject the gas first to an ionizing alternating voltage of sufilcient strength to efiect the ionization and then to subject the gas to the action of a pair of electrodes across which is impressed 2, low direct current voltage to cause the ions and electrons to travel to the electrodes. In 2% such cases, however, it is necessary that the gases have a certain speed of travel from the ionization field to the precipitation field. Ifthe gases are stagnant, the ions and electrons will travel to the ionization electrodes instead of the precipitation electrodes. This action is very detrimental to the purification of gas by this method since it is essential that the impurities be deposited on the precipitation electrodes rather than on the ionization electrodes. Moreover, the alternating voltage used in this method must necessarily be so high that there is considerable danger of sparking which is apt to cause an explosion when a dustladen gas is being treated. 4 r

The object of the present invention is to overcome these dificulties by superimposing the ionization field and the precipitation field upon each other, preferably by enclosing the ionization field in the precipitation field. By this arrangement, stagnant gas can be purified. Thus our invention has in view to effect the charging of the particles suspended within the gas by an opera-' tion involving two steps or stages and the use of two separate voltages and electric fields produced thereby. One of these voltages eflects the ioniza'tion of the gas, whereas the charging itself occurs in the field due to the other voltage which may be separately regulated and may at the same time, convey the charged particles to the precipitating electrodes. The ionization voltage and the precipitation voltage may also be impressed by (on. ree -#7) the same source of power and be mutually dependent upon each other, the failure 0! one causing the failure of the other, With our invention we obtain very effective precipitation and the suspended particles travel with great velocity to the precipitating electrodes so, that with an apparatus of short length a gas current of comparatively high velocity may be purified. The apparatus according to this invention is therefore of small dimensions. At the same time, the electrodes may be massive, and the very thin discharging wires used in ordinary purifying apparatus are not necessary. With this novel apparatus, the ionizing electrodes are free from precipitated particles, so that the working of the apparatus is not interfered with by covering of the ionization electrodes.

According to this invention the apparatus for the electrical purification of gases is provided with two sets of electrodes, fed by separate volt- 5 ages, the gaps and the fore the fields of these sets being placed subs ntiallyperpendicular to each other, and the field of one set of electrodes serving to produce ionization and thus establishing carriers of electricity, while the gas current is passed along these electrodes and between the other set of electrodes. The field of this other set serves for carrying the carriers oi electricity through the gas, the particles within the gas thus being charged and precipitated atthe precipitat- .ing electrodes. According to this method only the field due to the ionizer must berelatively strong. The additional field for carrying the ions or carriers of electricity through the gas and for charging the particles suspended within the gas can V be relatively low. This additional field may be supplied by a direct current voltage which need not be so high that any danger of sparking can arise. The combined action of the two fields makes it, possible to work with lower voltages by reason of some action, probably of the nature of induction, which is not understood. The combined action ofthe fields furthermore imparts greater activity to the particles in the gas and, in the case of gas purification, materially accelerates the process.

In carrying out this invention it is preferable to cover at least one of the electrodes, upon which the ionization voltage is impressed, with a layer of insulation and to arrange them close enough together so as to create a strong field between them with. the voltage impressed upon them. The electrodes upon which the direct voltage is impressed are preferably large, flat, parallel surfaces so arranged as to set up a field intersecting or 0 proximity to each other and suspended within the r embracing the field set up by the ionization electrodes.

The accompanying drawings illustrate one embodiment of our invention which embodiment is to be taken as illustrative rather than limitative. Figure -1 represents a diagrammatic view of applicants device; Figure 2 an elevation of the gas chamber enclosing the purification device. The gas chamber is designed by 0, two precipitating electrodes parallel to the walls, by p p. The electrodes are electrically connected to each other and to the earth. The ionizer 1' consists of a number of parallel round rods i 1', arranged in close chamber and at the same time insulated from its walls by the insulators m. It is important that sharp edges be avoided in order to eliminate all danger of sparking. Alternate rods are made entirely of, metal having conducting surfaces. The other rods 1 are covered with a layer of insulating material. The conducting rods, on the one hand, and the insulated rods, on the other hand, are connected in parallel. The transformer ti impresses an alternating voltage on the ionizer rods. The second transformer t in connection with the rectifier a and the condenser it, impresses a direct voltage across the precipitating electrodes and on the metal bars 01' the ionizer.

Both sets of electrodes are arranged within the gas chamber c. When applyin the invention for gas purification, the gas current to be purified is passed between the precipitating surfaces in the direction oi! the arrows the particles being ionized by the ionizer i and precipitated on the plates .being separate and independent from the other,

two sources of electric voltages one for independently feeding each set of said electrodes, one of said sets of electrodes so connected as to establish a strong electric alternating field for'producing carriers of electric charges, means for passing said gas along this set of electrodes, the second of said setsof electrodes so connected as to produce a second fleldpartly superimposed and across the first of said fields for producing migration of the carriers of electric charges across the stream of gas, thus charging the particles suspended within the gas.

2. A device in accordance with claim 1 and in. which a source of direct current is provided for producing said second field.

3. A device in accordance with claim 1, in which the ionizer consists of two parallel groups of linear conductors of difierent polarity, theoonductors of each group being connected to each, other in parallel, the conductors of both groups alternating and being arranged substantially in one plane.

4. A device in accordance with claim 1, in which the ionizer consists of two parallel groups of linear conductors of different polarity, the conductors of each group being connected to each other in parallel, the conductors of both groups alternating and being arranged substantially in one plane, the conductors of at least one group being covered with insulating-material.

5. A device in accordance with claim 1, in which the ionizer consists of two parallel groups or linear conductors of different polarity, the conductors of each group being connected-to each other in parallel, the conductors of both groups alternating and being arranged substantially in one plane, the electrodes of said other set consisting of two plates arranged at the sides of said ionizer, and the field between said plates and said ionizer being set up by a voltage independent from the ionizing voltage.

GEORG BRION. JOHANNES @UTZSCH. 

